At one point, each and every one of us has
gotten the sunscreen lecture: “If you use sunscreen you won’t get skin cancer,
and you won’t end up all wrinkly at the age of 45.” But how much truth does
this statement really hold? The purpose of this website is to find out the
real reason why we wear sunscreen (or why everyone tells us we should) and how
helpful it really is.

First of all, we all know that without sun
protection most people will get a sunburn, causing redness. A sunburn is the
result of cellular damage from ultraviolet radiation. The human body is built
to deal with damage by trying to repair it. Thus, when you get a sunburn, your
body increases blood flow to the skin in order to send in cells to repair the
damaged ones. This increased blood flow explains the redness of the skin. The
chemicals in sunscreens work by blocking, absorbing, or reflecting ultraviolet
light, thus decreasing the chance of sun damage.

Repeated sun damage is linked to premature
wrinkling, skin damage, and several types of skin cancer including melanoma,
basal, and squamous cell carcinoma. Studies indicate that severe sunburns
early on in life may increase chances for melanoma later in life.

Unfortunately, wearing
sunscreen does not guarantee that you will never get skin cancer. Sunscreen
helps prevent skin damage and skin cancer but there are other factors to take
into consideration.

First of all, you must wear sunscreen correctly. Liberally apply SPF
15 sunscreen or higher a half an hour before going out into the sun. Reapply
about every one and a half hours or after swimming, towel drying, or sweating.
What does SPF mean? SPF stands for sun protection factor and acts as a
multiplying factor. If you are normally safe in the sun for ten minutes, then
with an SPF 10 sunscreen you will be safe in the sun for one hundred minutes.
A higher SPF means a stronger
sunscreen.

Furthermore, the U.S.
Environmental Protection Agency recommends avoiding the sun during its
strongest hours between 10 a.m. and 4
p.m. and wearing a hat,
protective clothing and sunglasses during prolonged periods in the sun.

Finally, there may be one more somewhat surprising
thing to consider. The sun produces three types of rays; UVA, UVB, and UVC.
UVC rays are filtered out by the atmosphere, but the longer wavelengths of UVA
and UVB reach us on the Earth. However, most sunscreens do not offer
protection from UVA wavelengths. In fact, SPF applies only to UVB
wavelengths. Although some websites claim UVA rays are not harmful and can be
considered a safe way to tan, most emphasize the fact that no UV light is
safe. Products that claim “all day protection” and “broad spectrum sunblock”
offer protection from both UVA and UVB rays.

The above information and more about
sun protection can be found at the following websites:

Melanoma is a cancer of the pigment-producing cells
in your body. Over the past forty years, the incidence of melanoma has shown
an increasing trend worldwide. Melanoma is the severest of the skin cancers
due to its high lethality. Due to results showing sunscreen use has the ability
to reduce UVB – induced skin cancers, sunscreen has become an important part of
melanoma prevention. However, it is difficult to draw conclusions on the
degree of protection sunscreen offers from preventing melanoma because of
several confounding variables. These confounding variables may include
different risk factors, improper sunscreen use and human behavior towards the
sunlight.

The two major risk factors for melanoma are skin
sensitivity and exposure to ultraviolet radiation from the sun. Other risk
factors include age, sex, family history of melanoma, number of moles, and
exposure to artificial ultraviolet radiation. Risk factors are confounding
variables that may affect a sunscreen user’s chance of getting melanoma.
However, while people with more sensitive skin are at a greater use for
melanoma, these same people are more likely to use sunscreen. In this example,
sunscreen use cannot be linked with lower melanoma risk.

Improper sunscreen use is another important
confounding variable. A person may use sunscreen to protect against sunburn,
thus allowing themselves long sunbathing hours. However, sunscreens do not
protect the skin during prolonged exposure to the sun and thus sunscreen use
without a reduction in sun contact may not lessen risk for skin cancer. In one
experiment, “the group that received sunscreen with an SPF of 30 had higher
cumulative exposure to sun and longer daily sunbathing than did the group that
used sunscreen with an SPF of 10” (Dennis). This result proves that sunscreen
use is a confounding variable of sun exposure. Other factors of improper
sunscreen use involve persons not applying generous enough amounts of sunscreen
and not reapplying when necessary.

It should be mentioned that improper sunscreen use
may be the result of certain behaviors towards sunbathing. In our day and age,
suntans are considered more attractive and healthy looking than paler skin. “A
literature review carried out for the period between 1977 and 1998 showed that
intentional sun exposure is highly prevalent among youths, despite their
awareness of the risks involved in excessive exposure to ultraviolet radiation
and their knowledge on skin protection measures” (Souza). This type of
excessive sun exposure can cause the types of burns associated with melanoma.

Scientists limited knowledge of UVA rays influence
in development of melanoma also adds difficulty to the sunscreen-melanoma
relationship. Until fairly recently, UVB rays were considered the cancer
causing rays while UVA rays were left out of that equation. Now, the cause UVA
rays have in premature aging is increasingly recognized, as well as the
acceptance that UVA rays do play some part in melanoma risk. Since most
sunscreens are only UVB protective, sunscreen protected bathers may still be
putting themselves at risk for melanoma. However, to what effect UVA rays
effect melanoma risk is unknown.

In conclusion, although wearing
sunscreen will clearly lower one’s risk of developing melanoma, there are many
confounding variables to take into account when linking sunscreen to melanoma.
Because of these variables as well as new data on UVA rays, there haven’t been
any recent experiments that have clearly stated how much wearing sunscreen
reduces melanoma risk. In the future, I expect someone will conduct an
experiment with many controlling variables that will be able to answer this
question for us.